Artificial antigens. Synthesis of polyacrylamide copolymers containing 3-deoxy-D-manno-2-octulopyranosylonic acid (KDO) residues.

Starting from an anomeric mixture of methyl (allyl 4,5,7,8-tetra-O-acetyl-3-deoxy-alpha- and -beta-D-manno-2-octulopyranosid)onates, the glycosides sodium (allyl 3-deoxy-alpha- and -beta-D-manno-2-octulopyranosid)onate, sodium O-(sodium 3-deoxy-alpha-D-manno-2-octulopyranosylonate)-(2----4)-[allyl 3-deoxy-alpha-D-manno-2-octulopyranosid]onate and sodium (allyl 3-deoxy-7-O-beta-D-ribofuranosyl-beta-D-manno-2-octulopyranosid)++ +onate were prepared in several steps. Radical copolymerization of the allyl glycosides with acrylamide afforded linear macromolecular antigens containing mono- and di-saccharide residues corresponding to the KDO-region of Salmonella minnesota rough-form lipopolysaccharide and to partial structures of the capsular polysaccharide from Escherichia coli K 23, respectively. The copolymers were substituted by KDO-residues in a ratio of 1:18 +/- 2 (based on acrylamide) and had molecular masses of 60-100 kdaltons.